Take a look back at some of the best photos of defensive tackle Sheldon Richardson during his 2017 NFL season with the Seattle Seahawks. View

While looking ahead to 2018, Seahawks coach Pete Carroll expressed optimism about “a young nucleus and a new nucleus of guys that have come to us,” and he mentioned safety Bradley McDougald as a part of that group.

On Monday, the Seahawks made sure McDougald would be part of that nucleus going forward, signing the versatile safety to a multi-year contract extension just before the start of free agency.

McDougald, 27, joined the Seahawks last year after spending the first four years of his career in Tampa Bay, and despite being a somewhat under-the-radar signing, he was a player whom the Seahawks were very excited about when they acquired him last spring.

And McDougald indeed proved to be an important addition to the team in 2017, beginning the season as a key contributor on special teams while also playing as a third safety in “big nickel” packages, and finishing the season as a starter. One reason the Seahawks liked McDougald was his ability to play both safety spots, and he showed that versatility during the season, starting two games in place of Earl Thomas at free safety when Thomas had a hamstring injury, then finishing the year starting seven straight games for Kam Chancellor at strong safety after Chancellor sustained a season-ending neck injury.

McDougald finished the season with 67 tackles, fourth most on the team, and four passes defensed, while also contributing eight tackles on special teams, which was tied for second most on the team.

“It was exactly what we had hoped for,” Carroll said of McDougald last season as he transitioned from starting at free safety to strong safety. “We had seen great versatility in him and playmaking and leadership and all that kind of cool stuff that you hope to see, and when he got here, he just proved it. So he has been able to play nickel, he has played the big nickel, and he has just been able to do everything on special teams and be a leader and all of that. So he has been a fantastic addition and a little bit of an unsung hero at this time for this season, that he has been able to be so versatile and be so successful at what he is doing.”